Sample of First Chapter

Consider using LEDs to light a one-acre farm on Mars. Good solar panels have an efficiency of 22 percent, and great LEDs have an efficiency of 35 percent. With Mars' solar irradiance of 59 percent, you would need a minimum of 22 acres of solar panels for the plants to receive the same amount of light as on Earth.

For a small outpost, that is doable. But to feed Promise's population of 304,667, you would need 2,500 acres of greenhouse, which in turn would require you to build 55,000 acres of solar panels. That's 86 square miles, or a twentieth of all solar panels ever made. And that's for the lights alone. Luckily, no one farmed that way on Mars.

Having finished my count, I moved my hand down from where it blocked the sun's glare. I wrote "174 wheat plants per meter” in the top left corner of my notebook. Hmm. Well within normal. No decaying plant matter; no smell of rot. None of the cracks in the concrete floor had more than a two-millimeter gap. Where was all the oxygen going?

I was an accountant with the Mars Accountants and Resource Society. I was also confused. Greenhouse 211 produced less oxygen than the math said it should. In fact, it produced the least of all 309 greenhouses.

Oxygen accounting for a greenhouse is harder than for other facilities. Plants are unpredictable, and their oxygen production varies day to day. But in the end, a certain weight of product should equate to a certain weight of oxygen.

I walked over to a farmer filling a crack in the cement floor with rubber sealant. Greenhouses are softsuit areas, so it took a gentle prod to get his attention.

I asked, “Any trouble with the cracks lately?"

He straightened up and turned to squarely face me.

“I'm not hiding anything from MARS.”

Somewhat disgruntled that he could tell I worked for the Mars Accountants and Resource Society, I said, “I'm not making any accusations. I'm just looking to do my accounting.”

“That's probably what you told...